Process of making alkali perborates.



UNITED sTArEs PATENT OFFICE,

OTTO LIEBKNEOHT, OF FRANKFORT- ON-THE-MAIN, GERMAYY, ASSIGNOR TO THE ROESSLEli & HASSLACHER CHEMICAL COMPANY, OF N EYV YORK, N. Y., A CORPORATION OF NEW YORK. I

PROCESS OF MAKING ALKALI' P ERBORATES.

Patented Jan. 29, 1907.

application filed October 26, 1906.

No. 842,471. Specification of Letters Patent.

Original application filed February 7, 1906, Serial N 0, 299,901. Divided and this Serial No. 340,686,

To all whom it may concern.-

Be it known that I, 'Orro LIEBKNECHT, a subject of the German Emperor, and a resident of Frankfort-bn-the-Main, Germany, 5 have inventeda certain new and useful Process of Making Alkali Perborates, of which the following is a specification and which is a division of my application, Serial No. 299,901, filed February 7, 1906. r My invention relates to a new process of making alkali perborates which has proved easy in operation and of a high degree of efliciency. I have discovered that if an alkali peroxid, such as sodium peroxid, in solution or in suspension in water is treated With boracic acid and carbonic acid a perborate is formed and precipitated in an alkaline solution. As a result of my process besides the perborate a .pure concentrated solution of carbonate is obtained which can be used for other purposes.

In the following I have described. one illustrative method of carrying out the process as applied to the manufacture of sodium perborate, the features thereof being more particularly pointed out hereinafter in the claims.

Six hundred and thirty'parts of boracic acid are stirred into four thousand parts of water and then seven hundred and eighty parts of sodium peroxid are added, together with sufficient ice, so that no increase in temperature takes place. dust-free waste gases containing carbonic acid are passed into the mixture until fifty cubic centimeters of a filtered sample discolors but five to ten cubic centimeters of a one- -fifth normal potassium permanganate solution after an addition of sulfuric acid.

Then carbonic acid or The reaction of the illustrative process set forth is I-I BO Na O CO N aBO NaIrIOO H O.

A surplus of carbonic acid is not harmful, as the same does not decompose the alreadyformed perborate. It will be of advantage to stir during the entire operation. 'When the reaction is completed, the precipitate of perborate is separated from the sodium carbon: ate solution, washed out, and dried in the usual manner. q w

It is obvious thatthe process as described 7 may be varied without departing from the spirit of the invention and that the proportions stated are merely illustrative. For in-' stance, sodium peroxid may be replaced by other alkali peroxid, such as sodium potasslum peroXid or potassium peroXid, as long as there is enough alkali in the form of a salt present to produce perborate as a result of the reaction.

What I claim, and desire to secure by Letters Patent, is p 1. The process of making alkali perborates which consists in reacting on boracic acid with an alkali peroxid and carbon dioxid.

2. The process'ofmaking sodium perborate which consists in reacting on boracic acid with sodium peroXid and carbon dioXid.

In witness whereof I have hereunto signed '70 my name in the presence of two subscribing Witnesses.

' OTTO LIEBKNEOHT. Witnesses:

Honsr ZIEGLER, JEAN GRUND. 

